You don't know even a small fraction enough about what went on in regards to Mira and the board to be declaring that she is somehow suspect in the events that unfolded.

That last part that you wrote - any non greed ego driven person - is argumentum ad populum, which further undermines your statement. If had something more to support such a dramatic claim about Mira's character and role, you'd have brought it.

We don't know that she didn't give Sam a heads-up.

That being said, Mira was likely blindsided herself. She likely believed there was good reason. It's clear in hindsight that Sam likely wasn't wrong, but when the people Sam appointed to fire him if necessary say he's being fired, I don't think it's wrong if your gut reaction is to accept it.

Or...you call Sama and say "hey just an FYI, they asked me to be CEO and I said yes. I have no idea what's going on, and I'm loyal so keep me in the loop if we're going to leave or something".

Or, you're like "WTF is going on, I gotta figure this shit out"

...two days later...

"Oh I see now, you're all morons."

Not sure why you’re downvoted. It’s clearly sus.